CN113324565A

CN113324565A - Mechanical angle detection method, holder and machine-readable storage medium

Info

Publication number: CN113324565A
Application number: CN202110590574.9A
Authority: CN
Inventors: 周长兴
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2017-11-14
Filing date: 2017-11-14
Publication date: 2021-08-31
Also published as: CN108474671B; CN108474671A; WO2019095106A1

Abstract

A mechanical angle detection method, a holder and a machine-readable storage medium are provided, the method is applied to the holder provided with a Hall sensor and a magnetic coding sensor, and the method comprises the following steps: under the condition that the Hall sensor works normally, the mechanical angle measured by the Hall sensor is used for calibrating the magnetic coding sensor; and under the condition that the Hall sensor has a fault, determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the calibrated magnetic encoding sensor. The embodiment can realize the redundancy effect of the magnetic coding sensor and improve the stability of the holder.

Description

Mechanical angle detection method, holder and machine-readable storage medium

The application is a divisional application with application date of 2017, 11, and 14, application number of CN201780004920.2, and title of "mechanical angle detection method, holder and machine readable storage medium".

Technical Field

The application relates to the technical field of cloud platforms, in particular to a mechanical angle detection method, a cloud platform and a machine readable storage medium.

Background

The pan tilt is a steering shaft connected to the bottom of the optical device and the fixed support, and is used for supporting and stabilizing the optical device, such as a camera.

At present, for a small-sized tripod head, two schemes are provided for measuring the mechanical angle of a motor, wherein in the first scheme, a hall sensor is additionally arranged on the tripod head to measure the electrical angle of the motor, and then the mechanical angle of the motor is calculated based on the corresponding relation between the mechanical angle and the electrical angle. However, for a motor with more than two pole pairs, the electrical angle and the mechanical angle are not in one-to-one correspondence, so that after the tripod head is powered on each time, a 'collision limit' method is firstly adopted to obtain the one-to-one correspondence of the electrical angle and the mechanical angle, and the specific 'collision limit' method means that after the tripod head is powered on, the motor in the tripod head is firstly controlled to turn to one limit, when the motor collides the limit, the mechanical angle at the moment is set to be 0 degrees, the electrical angle calculated by the Hall sensor at the moment is recorded, then the motor is controlled to turn to the other limit, in the process that the motor turns to the other limit, the electrical angle variation measured by the Hall sensor is collected at a set frequency, the mechanical angle variation is further calculated, the mechanical angle can be obtained, and then the one-to-one correspondence of the electrical angle and the mechanical angle is recorded, and when the motor collides with another limit, subsequently, the electric angle of the motor is measured by the Hall sensor, and the mechanical angle can be calculated based on the one-to-one correspondence relationship between the electric angle and the mechanical angle. And secondly, a Hall magnet is arranged on a motor rotating shaft, the magnetic coding sensor is arranged right below the Hall magnet (the counter shaft is arranged for short) or the magnetic coding sensor is arranged beside the Hall magnet (the shaft is arranged for short), so that the Hall magnet rotates along with the motor rotating shaft in the rotating process of the motor, a magnetic field generated by the Hall magnet generates magnetic field intensity change of an alternating sine wave at any measuring position on the magnetic coding sensor, the change corresponds to the magnetic field intensity in a period of 0-360 degrees, a magnetic coding chip can identify the absolute position of the Hall magnet at a certain moment according to the sensed magnetic field intensity, and position information is output after being coded, so that the mechanical angle of the motor is measured.

As can be seen from the above description, in the first solution, since the "collision limit" method is executed after the pan/tilt is powered on each time, the process of measuring the mechanical angle of the motor by using the first solution is complicated, and the structural stability of the pan/tilt will be affected as the number of times of collision limit of the pan/tilt increases. In the second scheme, if the magnetic coding sensor and the hall magnet are placed in a counter shaft manner, although the accuracy of the calculated mechanical angle is high, the length of the whole holder is increased by placing the counter shaft, and the counter shaft placing manner is not applicable in a space with limited length; if the magnetic encoding sensor and the hall magnet are arranged on the shaft side, the deviation between the mechanical angle obtained through calculation and the real mechanical angle is large, and in order to improve the accuracy of the mechanical angle obtained through calculation, other tools are needed to carry out nonlinear calibration on the magnetic encoding sensor, so that the process of measuring the mechanical angle of the motor is complicated.

Disclosure of Invention

In view of the above, the present application discloses a mechanical angle detection method, a holder and a machine-readable storage medium.

In a first aspect, a mechanical angle detection method is provided, which is applied to a pan-tilt equipped with a hall sensor and a magnetic encoding sensor, and the method includes:

under the condition that the Hall sensor works normally, the mechanical angle measured by the Hall sensor is used for calibrating the magnetic coding sensor;

and under the condition that the Hall sensor has a fault, determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the calibrated magnetic encoding sensor.

Optionally, the magnetic encoding sensor is disposed on a medial side of the head.

Optionally, when the cradle head is in a first power-on state, the magnetic encoding sensor is calibrated by using the mechanical angle measured by the hall sensor.

Optionally, the calibrating the magnetic coding sensor by using the mechanical angle measured by the hall sensor includes:

in the process that a motor of the holder rotates from a first limit to a second limit, respectively acquiring a mechanical angle measured by the Hall sensor and a magnetic encoding value measured by the magnetic encoding sensor at the same sampling frequency;

and calibrating the magnetic coding sensor according to the incidence relation between the mechanical angle and the magnetic coding value.

Optionally, the determining a mechanical angle of the motor of the pan/tilt head according to the magnetic encoding value measured by the calibrated magnetic encoding sensor includes:

and determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the magnetic encoding sensor and the incidence relation.

Optionally, the mechanical angle acquired at the same sampling instant is the same as the state of the electric machine indicated by the magnetically encoded value.

Optionally, the calibrating the magnetic coding sensor includes:

determining the corresponding relation between the mechanical angle and the magnetic coding value according to the mechanical angle and the magnetic coding value acquired at the same sampling moment;

the determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the calibrated magnetic encoding sensor comprises the following steps:

and determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the magnetic encoding sensor and the corresponding relation.

Optionally, there are multiple pairs of correspondence between the mechanical angle and the magnetically encoded value;

the determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the magnetic encoding sensor and the corresponding relationship comprises:

determining a fifth magnetic encoding value smaller than the magnetic encoding value measured by the magnetic encoding sensor and a sixth magnetic encoding value larger than the magnetic encoding value measured by the magnetic encoding sensor from the plurality of pairs of magnetic encoding values of the correspondence;

and determining the mechanical angle of the motor of the holder according to the mechanical angle corresponding to the fifth magnetic encoding value and the mechanical angle corresponding to the sixth magnetic encoding value.

Optionally, the fifth magnetic encoding value is a largest one of all magnetic encoding values smaller than the magnetic encoding value measured by the magnetic encoding sensor;

the sixth magnetic encoded value is a smallest one of all magnetic encoded values that are greater than the magnetic encoded value measured by the magnetic encoded sensor.

Optionally, the mechanical angle of the motor of the pan/tilt head is obtained by performing linear interpolation according to a linear relationship between the mechanical angle corresponding to the fifth magnetic encoding value and the mechanical angle corresponding to the sixth magnetic encoding value.

Optionally, the method further comprises:

and controlling a holder shaft of the holder to rotate according to the mechanical angle of the motor of the holder.

In a second aspect, a cradle head is provided, the cradle head comprising a motor, a magnetic encoding sensor, a hall sensor and a processor;

the Hall sensor is used for measuring to obtain a mechanical angle;

the Hall sensor is used for measuring to obtain a magnetic coding value;

the processor is used for calibrating the magnetic coding sensor by using the mechanical angle measured by the Hall sensor under the condition that the Hall sensor normally works; and under the condition that the Hall sensor has a fault, determining the mechanical angle of the motor of the holder according to the magnetic encoding value measured by the calibrated magnetic encoding sensor.

In a third aspect, a machine-readable storage medium is provided, on which computer instructions are stored, which when executed implement the mechanical angle detection method according to any one of the first aspect.

According to the embodiment, the Hall sensor and the magnetic coding sensor are arranged on the cradle head at the same time, so that the magnetic coding sensor is calibrated according to the mechanical angle measured by the Hall sensor when the Hall sensor works normally, the mechanical angle of the motor in the cradle head can be measured by the magnetic coding sensor independently after the Hall sensor fails, and the redundancy effect of the magnetic coding sensor can be realized and the stability of the cradle head is improved through the processing.

Drawings

FIG. 1 is a schematic structural view of a tripod head according to the present invention;

FIG. 2 is a flowchart illustrating a method for detecting a mechanical angle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the relationship between electrical angle and mechanical angle;

FIG. 4 is a flowchart illustrating another embodiment of a method for detecting a mechanical angle according to the present invention;

FIG. 5 is a flow chart of another embodiment of the mechanical angle measuring method of the present invention;

FIG. 6 is a flow chart of another embodiment of a method of measuring a mechanical angle of the present invention;

FIG. 7 is a flow chart of another embodiment of a method of measuring a mechanical angle of the present invention;

fig. 8 is a block diagram of one embodiment of a pan and tilt head.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

At present, for a small-sized tripod head, a hall sensor can be arranged on the tripod head to measure the electric angle of a motor in the tripod head, and then the mechanical angle of the motor is calculated according to the one-to-one correspondence relation between the electric angle and the mechanical angle obtained by adopting a collision limit method when the tripod head is electrified every time; or, a magnetic coding sensor is arranged on the tripod head, so that the mechanical angle of a motor in the tripod head can be directly measured through the magnetic coding sensor.

However, if the hall sensor is used to measure the mechanical angle of the motor, the collision limit method is executed after the cradle head is powered on every time, so the process of measuring the mechanical angle of the motor by using the hall sensor is complicated, and the structural stability of the cradle head is affected as the number of times of collision limit of the cradle head is increased; if a magnetic coding sensor is additionally arranged in the cradle head in a mode of placing the cradle head in a counter shaft, the length of the whole cradle head is increased, so that the mode is not suitable for a small cradle head; if the magnetic coding sensor is additionally arranged in the holder in a shaft side placing mode, the precision requirement on the magnetic coding sensor is high, the high-precision magnetic coding sensor is very expensive, meanwhile, the low-precision magnetic coding sensor cannot meet the requirement of the holder on the precision of the mechanical angle, and other tools are required to perform nonlinear calibration on the magnetic coding sensor in order to improve the accuracy of the mechanical angle measured by the low-precision magnetic coding sensor, so that the method for measuring the mechanical angle of the motor has a great deal of limitation.

Based on this, in the embodiment of the present invention, it is proposed to simultaneously provide a hall sensor and a magnetic encoder sensor on a pan/tilt, where the magnetic encoder sensor may be a low-precision magnetic encoder sensor in consideration of cost, and an axial side placement manner is adopted to reduce the size of the pan/tilt, as shown in fig. 1, which is a schematic structural diagram of the pan/tilt according to the present invention. In the embodiment of the invention, the Hall sensor and the magnetic coding sensor are arranged on the holder at the same time, so that the following effects can be realized: when the Hall sensor works normally, the magnetic coding sensor assists the Hall sensor to measure the mechanical angle of the motor in the holder so as to control the holder shaft in the holder to act according to the mechanical angle of the motor, and through the processing, the problems that when the Hall sensor measures the mechanical angle of the motor in the holder independently, the mechanical angle measuring process is complicated and the structural stability of the holder is influenced due to the fact that the 'collision limit' process is required to be executed after each power-on process can be avoided; meanwhile, the magnetic coding sensor can be calibrated according to the mechanical angle measured by the Hall sensor when the Hall sensor works normally, so that the mechanical angle of the motor in the cradle head can be measured by the magnetic coding sensor independently after the Hall sensor fails, the redundancy effect of the magnetic coding sensor can be realized through the processing, and the stability of the cradle head is improved.

The following examples are listed below to illustrate the mechanical angle detection method provided by the present invention:

the first embodiment is as follows:

referring to fig. 2, a flowchart of an embodiment of a method for detecting a mechanical angle according to the present invention is shown, where the method includes the following steps:

step 201: and acquiring a magnetic encoding value measured by a magnetic encoding sensor arranged on the holder.

Step 202: and acquiring the electrical angle measured by a Hall sensor arranged on the pan-tilt.

Step 203: and determining the mechanical angle of a motor in the holder according to the magnetic coding value and the electric angle.

The above steps 201 to 203 are explained as follows:

in the embodiment of the present invention, after the cradle head is put into use, the process of measuring the mechanical angle of the motor in the cradle head can be generally divided into two processes, wherein the first process is as follows: when the holder is in an initial state, namely when the holder is powered on at first, measuring an initial mechanical angle of a motor in the holder; the second process is: when the holder is in a working state, the current mechanical angle of the motor in the holder is measured so as to control the holder shaft in the holder to move according to the current mechanical angle.

First, the first process described above will be explained:

when the holder is in an initial state, acquiring a magnetic encoding value measured by a magnetic encoding sensor arranged on the holder, for convenience of description, referring the magnetic encoding value acquired at the moment to be an initial magnetic encoding value, and simultaneously acquiring an electrical angle measured by a Hall sensor arranged on the holder, for convenience of description, referring the electrical angle acquired at the moment to be an initial electrical angle. Subsequently, the initial mechanical angle of the motor in the holder can be determined according to the initial magnetic coding value and the initial electrical angle.

In an embodiment, the process of determining the initial mechanical angle of the motor in the pan/tilt head from the initial magnetic encoding value and the initial electrical angle may include: firstly, determining the magnetic encoding value range to which the initial magnetic encoding value belongs according to the preset magnetic encoding value range, then determining the electric angle period to which the initial magnetic encoding value belongs according to the corresponding relation between the preset magnetic encoding value range and the electric angle period, and finally determining the initial mechanical angle of the motor in the holder according to the electric angle period and the initial electric angle.

First, the "electrical angle period" will be explained as follows:

it will be understood by those skilled in the art that the electrical angle is defined according to a complete cycle change of current, from an electromagnetic point of view, a complete cycle of 360 degrees electrical angle is referred to as an electrical angle cycle, where the electrical angle cycle is related to the number of antipodes of the motor, specifically, the motor has several antipodes, and when the motor rotates a mechanical angle of 0 to 360 ° in a spatial angle, the electrical angle will complete a change of several electrical angle cycles, and each electrical angle cycle will correspond to a mechanical angle range.

For example, assuming that the motor in the pan/tilt head has 4 opposite poles, when the motor rotates a mechanical angle of 0 to 360 ° in a spatial angle, the electrical angle will complete a change of 4 electrical angle periods, and for the convenience of description, the 4 electrical angle periods may be referred to as a first electrical angle period, a second electrical angle period, a third electrical angle period, and a fourth electrical angle period, respectively. The mechanical angle range corresponding to the first electrical angle period is 0-90 degrees, the mechanical angle range corresponding to the second electrical angle period is 90-180 degrees, the mechanical angle range corresponding to the third electrical angle period is 180-270 degrees, the mechanical angle range corresponding to the fourth electrical angle period is 270-360 degrees, and further, the following relations exist between the electrical angles and the mechanical angles in different electrical angle periods:

first electrical angle period: mechanical angle is equal to electrical angle/4;

second electrical angle period: mechanical angle ═ electrical angle/4 +90 °;

third electrical angle period: mechanical angle ═ electrical angle/4 +180 °;

fourth electrical angle period: mechanical angle is equal to electrical angle/4 +270 °.

In order to make the relationship between the electrical angle and the mechanical angle described above more clearly understood by those skilled in the art, fig. 3 is shown below, and as shown in fig. 3, is a schematic diagram of the relationship between the electrical angle and the mechanical angle.

Up to this point, the description on the "electrical angle period" is completed.

Subsequently, based on the above description of the electrical angle period, the first process is described in detail:

continuing with the example of 4 pairs of motors in the pan/tilt head, assume that the correspondence between the preset magnetic encoding value range and the electrical angle period is shown in table 1 below:

TABLE 1

Range of magnetically encoded values	Period of electrical angle
		[A0，A1]	First electrical angle period
[A2，A3]	Second electrical angle period
		[A4，A5]	Third electrical angle period
[A6，A7]	Fourth electrical angle period

Assuming that the initial magnetic encoding value is m0, the initial electrical angle value is e0, and assuming that m0 is located between a2 and A3, that is, the initial magnetic encoding value belongs to the magnetic encoding value range of [ a2, A3], as can be seen from table 1, the magnetic encoding value range of [ a2, A3] corresponds to the second electrical angle period, that is, the initial magnetic encoding value belongs to the second electrical angle period, then the initial mechanical angle of the motor in the pan/tilt head can be calculated by the following formula (one).

Initial mechanical angle e0/4+90 degree equation (one)

It is to be briefly explained here that the correspondence between the magnetic encoding value range and the electrical angle period may be set before the cradle head is put into use, that is, before the cradle head leaves the factory, and specifically, how to set the correspondence between the magnetic encoding value range and the electrical angle period may be referred to the description in the following embodiment two, which is not described in detail herein.

To this end, the description about the first process is completed.

Next, the second process described above will be explained:

when the holder is in the working state, the electrical angle measured by the hall sensor arranged on the holder can be obtained at a set sampling frequency, for example, every 1 second, for convenience of description, the sampling frequency is called as a second sampling frequency, and subsequently, when the holder is in the working state, the current mechanical angle of the motor in the holder can be determined according to the electrical angle and the initial mechanical angle obtained in the first process, so as to control the holder shaft in the holder to move according to the current mechanical angle.

In an embodiment, the process of determining the current mechanical angle of the motor in the pan/tilt head according to the electrical angle and the initial mechanical angle may include: firstly, according to the electric angle obtained at present and the electric angle obtained at the previous sampling moment, determining the electric angle variation between the electric angle obtained at present and the initial electric angle, secondly, determining the mechanical angle variation according to the electric angle variation and the number of antipodes of the motor in the holder, and finally, determining the current mechanical angle of the motor in the holder according to the initial mechanical angle and the mechanical angle variation.

In order that those skilled in the art may more clearly understand the above process, the following examples are shown:

first, a process of determining an electrical angle variation between a currently acquired electrical angle and an initial electrical angle according to the currently acquired electrical angle and an electrical angle acquired at a previous sampling time will be described by way of example:

the first embodiment is as follows:

assuming that the initial electrical angle of the motor in the cradle head is 120 degrees in the initial state, and the initial electrical angle belongs to the second electrical angle period, after the cradle head enters the working state, the motor starts to rotate from the second electrical angle period, and the motor can turn to the third electrical angle period and also can turn to the first electrical angle period. In the working process of the tripod head, the electrical angle measured by the hall sensor in the tripod head is obtained at the first sampling frequency, the electrical angle obtained by one-time sampling is assumed to be 150 degrees, the currently obtained electrical angle is compared with the initial electrical angle, it can be found that the difference value between the two is 30 degrees and is smaller than a preset threshold value, for example, 180 degrees, the motor can be determined to be still in the second electrical angle period at the moment, and the motor rotates towards the third electrical angle period, so that the electrical angle variation between the currently obtained electrical angle and the electrical angle obtained at the previous sampling moment is 30 degrees.

The description of example one is thus completed.

Example two:

assuming that the initial electrical angle of the motor in the pan/tilt head is 300 ° in the initial state, and the initial electrical angle belongs to the second electrical angle period, and assuming that the electrical angles obtained by sampling 3 times before and after are 330 °, 360 °, and 30 °, in the sampling process, after the electrical angle is obtained by sampling each time, it can be determined whether the difference between the electrical angle obtained currently and the electrical angle obtained at the previous sampling time is greater than a preset threshold, for example, after the electrical angle is obtained by sampling 30 °, it is determined that the difference between the electrical angle obtained currently and the electrical angle obtained at the previous sampling time is 330 °, and is greater than the preset threshold 180 °, it can be considered that a jump of the electrical angle period occurs between 360 ° and 30 °, and the electrical angle obtained currently is smaller than the electrical angle obtained at the previous sampling time, with reference to the schematic diagram of fig. 3, it will be understood by those skilled in the art that when the motor jumps from the second electrical angle period in the initial state to the third electrical angle period after one jump of the electrical angle period, the electrical angle change between the currently acquired electrical angle and the initial electrical angle is 90 ° (360 ° -300 ° +30 °).

So far, the description of example two is completed.

Example three:

assuming that the initial electrical angle of the motor in the pan/tilt head is 60 ° in the initial state, and the initial electrical angle belongs to the second electrical angle period, and assuming that the electrical angles obtained by sampling 3 times before and after are 30 ° and 360 °, as in the above example, in the sampling process, after the electrical angle is obtained by sampling each time, it can be determined whether the difference between the currently obtained electrical angle and the electrical angle obtained at the previous sampling time is greater than the preset threshold, for example, after the electrical angle is obtained by sampling 360 °, it is determined that the difference between the currently obtained electrical angle and the electrical angle obtained at the previous sampling time is 330 ° and greater than the preset threshold 180 °, it can be considered that a jump of the electrical angle period occurs between 30 ° and 360 °, and the currently obtained electrical angle is greater than the electrical angle obtained at the previous sampling time, as will be understood by those skilled in the art in conjunction with the schematic diagram of fig. 3, when the motor jumps from the second electrical angle period in the initial state to the first electrical angle period after one jump of the electrical angle period, the electrical angle change between the currently acquired electrical angle and the initial electrical angle is 60 ° (360 ° -360 ° +60 °).

So far, the description of the third embodiment is completed.

So far, the relevant description of the process of determining the electrical angle variation between the currently acquired electrical angle and the initial electrical angle according to the currently acquired electrical angle and the electrical angle acquired at the previous sampling time is completed.

Next, a process of "determining the mechanical angle variation amount according to the electrical angle variation amount and the number of antipodes of the motor in the pan/tilt head" will be described:

assuming that the motor has 4 pairs of poles and assuming that the amount of electrical angle change is Δ E, then the amount of mechanical angle change can be determined by the following equation (two):

mechanical angle variable quantity ═ delta E/4 formula (II)

So far, the related description of the process of determining the mechanical angle variation according to the electrical angle variation and the number of opposite poles of the motor in the holder is completed.

Finally, the process of determining the current mechanical angle of the motor in the holder according to the initial mechanical angle and the mechanical angle variation is exemplified:

example four:

with reference to the first example, the motor in the pan/tilt is still in the second electrical angle period at the current moment, and rotates in the direction of the third electrical angle period, and then, with reference to the schematic diagram of fig. 3, the current mechanical angle of the motor in the pan/tilt is equal to the sum of the initial mechanical angle and the mechanical angle variation.

So far, the description of example four is completed.

Example five:

with reference to the second example, if the motor in the pan/tilt head is in the third electrical angle period at the current time, then, with reference to the schematic diagram of fig. 3, the current mechanical angle of the motor in the pan/tilt head is equal to the sum of the initial mechanical angle and the mechanical angle variation.

The description of example five is now complete.

Example six: with reference to the third example, the motor in the pan/tilt head is in the first electrical angle period at the current moment, and then, with reference to the schematic diagram of fig. 3, the current mechanical angle of the motor in the pan/tilt head is equal to the difference between the initial mechanical angle and the mechanical angle variation.

Thus, the description of example six is completed.

It can be seen from the above embodiments that, in the normal working process of the cradle head, the hall sensor and the magnetic encoder sensor are simultaneously arranged on the cradle head, and the mechanical angle of the motor can be determined according to the electrical angle measured by the hall sensor and the initial mechanical angle measured by the magnetic encoder sensor and the auxiliary hall sensor, so that the situation that the corresponding relation between the electrical angle and the mechanical angle of the motor in the cradle head is determined by adopting a 'collision limit' method when the cradle head is powered on can be avoided.

The description of the first embodiment is completed.

In the embodiment of the present invention, the following two embodiments are shown to illustrate the process of setting the correspondence between the magnetic encoding value range and the electrical angle period in the present invention.

Example two:

referring to fig. 4, a flowchart of another embodiment of the mechanical angle detecting method of the present invention is shown, where the embodiment focuses on a process of setting a correspondence between a magnetic encoding value range and an electrical angle period, and may include the following steps:

step 401: when the holder is in a set state, the motor is controlled to rotate to a first limit position, and a first magnetic encoding value currently measured by the magnetic encoding sensor is recorded.

In the embodiment of the invention, before the holder is put into use, namely before the holder leaves a factory, the corresponding relation between the range of the magnetic coding value and the electric angle period is set for the holder.

In an embodiment, the setting state may be a first power-on state, that is, a first power-on state before the cradle head leaves a factory.

In an embodiment, when the cradle head is in a set state, the motor in the cradle head is controlled to rotate to a first limit position, and when the motor rotates to the first limit position, the magnetic encoding value measured by the magnetic encoding sensor at the moment is recorded.

Step 402: and controlling the motor to rotate from the first limit position to the second limit position, and acquiring a plurality of electrical angles measured by the Hall sensor at a set second sampling frequency and a plurality of magnetic encoding values measured by the magnetic encoding sensor at the second sampling frequency in the process that the motor rotates from the first limit position to the second limit position.

In one embodiment, the pan/tilt head can control the motor to rotate from the first limit to the second limit at a set angular velocity.

In one embodiment, in the process that the motor rotates from the first limit position to the second limit position, the electrical angles measured by the hall sensor are acquired at the set sampling frequency to obtain a plurality of electrical angles, and the magnetic coding values measured by the magnetic coding sensor are acquired at the same sampling frequency to obtain a plurality of magnetic coding values. For convenience of description, the sampling frequency is referred to as a first sampling frequency.

Step 403: and if the difference value between the currently acquired electrical angle and the acquired previous electrical angle is larger than a preset threshold value, recording a second magnetic coding value acquired at the same time as the previous electrical angle, and recording a third magnetic coding value acquired at the same time as the currently acquired electrical angle.

In the embodiment of the present invention, in the process of rotating the motor from the first limit to the second limit, each time an electrical angle is acquired, the electrical angle may be compared with an acquired previous electrical angle, if a difference between the two electrical angles is greater than a preset threshold, for example, 180 °, it may be considered that a jump occurs in an electrical cycle between a previous sampling time and a current sampling time, at this time, a magnetic encoding value acquired after the jump occurs in the electrical cycle, that is, at the current time may be recorded.

Step 404: and when the motor rotates to the second limit position, recording a fourth magnetic coding value currently measured by the magnetic coding sensor.

In the embodiment of the present invention, when the motor rotates to the second limit position, the magnetic encoding value currently measured by the magnetic encoding value sensor may be recorded, and for convenience of description, the magnetic encoding value is referred to as a fourth magnetic encoding value.

Step 405: and determining an effective magnetic encoding value range according to the first magnetic encoding value, the second magnetic encoding value, the third magnetic encoding value and the fourth magnetic encoding value, and determining an electric angle period corresponding to the effective magnetic encoding value range.

In the embodiment of the present invention, it can be known by combining the above-mentioned process of recording the second magnetic encoding value and the third magnetic encoding value that the sampling times corresponding to the second magnetic encoding value and the third magnetic encoding value are adjacent to each other, that is, the range between the second magnetic encoding value and the third magnetic encoding value does not correspond to any electrical angle period, that is, the range between the second magnetic encoding value and the third magnetic encoding value is determined as an invalid magnetic encoding value range.

Specifically, first, the first magnetic encoding value, the second magnetic encoding value, the third magnetic encoding value, and the fourth magnetic encoding value may be sorted according to a sampling sequence, then, each two adjacent magnetic encoding values are divided into a group according to a sorting result, a plurality of groups are obtained, and finally, for each group, if there are magnetic encoding values obtained by other sampling between two magnetic encoding values in the group, a magnetic encoding value range corresponding to the group is determined as an effective magnetic encoding value range, and a corresponding electrical angle period is determined for each effective magnetic encoding value range.

The above steps 401 to 405 are described by way of example as follows:

when the pan-tilt head is in a set state, the motor is controlled to rotate to a first limit position, a first magnetic code value measured currently by the magnetic code sensor is recorded, for example, A0, then the motor is controlled to rotate from the first limit position to a second limit position, in the rotating process, if a difference value between an electric angle acquired at a certain sampling time and an electric angle acquired at a previous sampling time is larger than a preset threshold value, a third magnetic code value acquired at the current sampling time is recorded, for example, A2, a second magnetic code value acquired at the previous sampling time is recorded, for example, A1, and the operations are repeated, if in the rotating process, the recorded magnetic code values are sequentially A1, A2, A3, A4, A5, A6, A7 and A8, and finally, when the motor collides with the second limit position, a fourth magnetic code value acquired at this time is recorded, for example, A9.

Then, the recorded magnetic encoding values are sorted according to the sequential order of the samples to obtain a sequence of magnetic encoding values a0, a1, a2, A3, A4, A5, A6, A7, A8, a9, and according to the sorting result, 9 groups of [ a0, a1], (a1, a2), [ a2, A3], (A3, A4), [ A4, A5], (A5, A6), [ A6, A7], (A7, A8), [ A8, a9], are obtained by grouping each two adjacent magnetic encoding values.

For each of the 9 groups, if there are other sampled magnetic code values between two magnetic code values in the group, for example, the sampling time instants of two magnetic code values in the group [ a0, a1], [ a2, A3], [ a4, a5], [ a6, a7], [ A8, a9] are not adjacent, so that there are other sampled magnetic code values between two magnetic code values in the 5 groups, the magnetic code value range corresponding to each of the 5 groups may be determined as the effective magnetic code value range.

And wherein the range of effective magnetically encoded values represented by [ A0, A1] corresponds to a first electrical angle period; the range of effective magnetic encoding values represented by [ A2, A3] corresponds to a second electrical angle period; the range of effective magnetic encoding values represented by [ A4, A5] corresponds to a third electrical angle period; the range of effective magnetic encoding values represented by [ A6, A7] corresponds to a fourth electrical angle period; due to the periodicity of the electrical angle, the range of valid magnetic encoding values represented by [ A8, A9] also corresponds to the first electrical angle period.

It should be noted that the possible existence of the range of valid magnetic encoding values [ A8, a9] is due to the periodicity of electrical and mechanical angles, the electrical cycle jumps by more than 4 (number of opposite poles of the motor), and thus [ A8, a9] returns to the first electrical angle cycle.

In addition, in the second embodiment of the present invention, the range of magnetic encoding values to which the initial magnetic encoding value belongs is determined, that is, the range of effective magnetic encoding values to which the initial magnetic encoding value belongs is determined, in combination with the description of the range of effective magnetic encoding values in the second embodiment.

In addition, because the initial magnetic encoding value is not guaranteed to belong to the range of the effective magnetic encoding value, when the initial magnetic encoding value does not belong to any range of the effective magnetic encoding value, it cannot be determined which electric angle period the initial electric angle acquired at the time belongs to, so that in order to determine the initial mechanical angle of the motor, the embodiment of the invention provides that if the initial magnetic encoding value is determined not to belong to any range of the effective magnetic encoding value, the motor can be controlled to rotate by a set angle, and then the initial magnetic encoding value measured by the magnetic encoding sensor is acquired again, and if the initial magnetic encoding value acquired again does not belong to any range of the effective magnetic encoding value, the motor can be controlled to rotate by a set angle continuously until the acquired initial magnetic encoding value belongs to one range of the effective magnetic encoding values.

In addition, in order to avoid that the set corresponding relationship is not accurate and the subsequent measurement of the mechanical angle of the motor is affected when the motor shakes in an external environment, that is, the corresponding relationship between the magnetic encoding value range and the electrical angle period starts to be set, in the embodiment of the present invention, before the step 401 is executed, it is proposed that whether the motor in the pan/tilt is in a stable state is firstly judged, and if so, the step 401 is executed.

Specifically, before the step 401 is executed, the variance of the magnetic encoding values is calculated according to the magnetic encoding values measured by the set number of magnetic encoding sensors, and if the variance exceeds a variance threshold, it can be known from the mathematical concept that the variation range between the magnetic encoding values is large, so that the motor is considered to be not stable currently.

It can be seen from the above embodiments that, when the pan/tilt head is in the set state, the motor in the pan/tilt head is controlled to complete a rotation process from the first limit position to the second limit position, and in the rotation process, the time when the electrical angle period jumps is determined according to the electrical angle measured by the hall sensor, so as to divide the electrical angle period, and the magnetic encoding value range corresponding to each electrical angle period is determined according to the magnetic encoding value measured by the magnetic encoding sensor, so that the electrical angle period to which the electrical angle measured by the hall sensor belongs can be subsequently determined according to the magnetic encoding value measured by the magnetic encoding sensor.

So far, the description of the second embodiment is completed.

In the embodiment of the invention, in order to improve the stability of the cradle head and realize the redundancy effect of the magnetic coding sensor, so that the magnetic coding sensor is utilized to the maximum extent, the invention also provides that the magnetic coding sensor independently measures the mechanical angle of the motor in the cradle head after the Hall sensor fails, and in order to realize the function that the magnetic coding sensor independently measures the mechanical angle of the motor in the cradle head, the magnetic coding sensor can be calibrated according to the mechanical angle measured by the Hall sensor when the Hall sensor normally works, specifically, the corresponding relation between the magnetic coding value and the mechanical angle can be calibrated, so that the subsequent magnetic coding sensor can determine the mechanical angle of the motor in the cradle head according to the magnetic coding value measured by the subsequent magnetic coding sensor and the corresponding relation.

As follows, the following embodiments are first shown to describe the process of "calibrating a magnetic encoder sensor based on a mechanical angle measured by a hall sensor".

Example three:

referring to fig. 5, a flowchart of another embodiment of the mechanical angle measuring method of the present invention is shown, where the embodiment focuses on the process of calibrating the magnetic encoder sensor according to the mechanical angle measured by the hall sensor, and may include the following steps:

step 501: when the holder is in a set state, the motor is controlled to rotate to a first limit position.

In one embodiment, when the holder is in the set state, the motor is controlled to rotate to the first limit position.

Step 502: and controlling the motor to rotate from the first limit position to the second limit position, and acquiring the mechanical angle measured by the Hall sensor in the process that the motor rotates from the first limit position to the second limit position.

In an embodiment, the motor may be controlled to rotate at a set angular velocity from a first limit to a second limit.

In one embodiment, the mechanical angle measured by the hall sensor is obtained at a set sampling frequency during the rotation of the motor from the first limit to the second limit. For convenience of description, the sampling frequency is referred to herein as a third sampling frequency.

Step 503: and acquiring the magnetic encoding value measured by the magnetic encoding sensor.

In one embodiment, the magnetic code values measured by the magnetic code sensor are acquired according to the same sampling frequency as in step 502 above, i.e., the third sampling frequency.

Step 504: an association between the magnetically encoded values and the mechanical angle is determined.

In the

above steps

502 and 503, the magnetic code value and the mechanical angle are obtained at the same sampling frequency, and then at the same sampling time, the obtained magnetic code value and the mechanical angle correspond to the same motor state, so that the corresponding relationship between the magnetic code value and the mechanical angle obtained at the same sampling time can be established, for example, as shown in the following table 2, which is an example of the corresponding relationship between the magnetic code value and the mechanical angle:

TABLE 2

Magnetically encoded value	Mechanical angle
		B1	R1
B2	R2
		B3	R3
…	…

In addition, it should be noted that the process of calibrating the magnetic encoder sensor by using the mechanical angle measured by the hall sensor described in the third embodiment may occur in the process of rotating the same motor from the first limit position to the second limit position, or may be implemented by two rotation processes, respectively, with the process of establishing the correspondence between the magnetic encoding value range and the electrical angle period by using the electrical angle measured by the hall sensor and the magnetic encoding value measured by the magnetic encoder sensor described in the second embodiment.

It can be seen from the above embodiments that, since the calibration of the magnetic encoder sensor is performed by using the mechanical angle measured by the hall sensor to set the corresponding relationship between the magnetic encoder value and the mechanical angle, compared with the prior art, no other tool is required to calibrate the magnetic encoder sensor, thereby simplifying the nonlinear calibration of the magnetic encoder sensor.

So far, the description of the third embodiment is completed.

As follows, the following embodiment is shown in conjunction with the third embodiment, and the following embodiment is described for the process of "the magnetic encoder sensor measures the mechanical angle of the motor in the pan/tilt head alone" in the present invention:

example four:

referring to fig. 6, a flowchart of another embodiment of the method for measuring a mechanical angle according to the present invention is shown, where the embodiment focuses on a process of measuring a mechanical angle of a motor in a pan/tilt head by using a magnetic encoder sensor, and the method may include the following steps:

step 601: and acquiring the magnetic coding value measured by the magnetic coding sensor after the Hall sensor fails.

Step 602: and determining the current mechanical angle of the motor in the holder according to the magnetic coding value and the incidence relation between the preset magnetic coding value and the mechanical angle.

In the embodiment of the present invention, taking the correspondence between the magnetic encoding values and the mechanical angles as an example in table 2 above, first, the correspondence is sorted according to the order of the magnetic encoding values in each correspondence from small to large, and it is assumed that the sorting result is shown in table 2 above, then, the sorting result is searched according to the magnetic encoding values obtained in step 601, and a first magnetic encoding value greater than the obtained magnetic encoding value is found.

Subsequently, according to the corresponding relationship illustrated in table 2, a mechanical angle corresponding to the fifth magnetic encoding value is obtained, for convenience of description, the mechanical angle is referred to as a fifth mechanical angle, and a mechanical angle corresponding to the sixth magnetic encoding value is obtained, for convenience of description, the mechanical angle is referred to as a sixth mechanical angle, and then, linear interpolation is performed according to a linear relationship between the fifth mechanical angle and the sixth mechanical angle, so as to obtain the current mechanical angle of the motor in the pan/tilt head.

For example, assuming that the magnetic encoding value obtained in step 601 is B1, and B1 is located between B1 and B2 illustrated in table 2, the fifth mechanical angle is R1, and the sixth mechanical angle is R2, and the current mechanical angle of the motor in the pan/tilt head can be calculated by the following formula (three).

Mechanical angle (1-alpha) R1+ alpha R2 formula (III)

In the above formula (iii), α is (B1-B1)/(B2-B1).

It will be understood by those skilled in the art that the above formula (three) is only an example, and other formulas are possible according to the specific algorithm of linear interpolation in the data concept, and the invention is not limited thereto.

According to the embodiment, after the Hall sensor fails, the magnetic coding sensor can be used for independently measuring the electric angle of the motor in the holder, so that the redundancy effect of the magnetic coding sensor can be realized, and the stability of the holder is improved.

So far, the description of the fourth embodiment is completed.

In addition, in the embodiment of the present invention, different from the first embodiment, other implementation processes may also be adopted to complete the process of measuring the mechanical angle of the motor in the pan/tilt head by using the hall sensor assisted by the magnetic encoding sensor, which specifically includes the following steps:

example five:

referring to fig. 7, a flowchart of another embodiment of a method for measuring a mechanical angle according to the present invention is shown, the method may include the following steps:

step 701: and acquiring a magnetic encoding value measured by a magnetic encoding sensor arranged on the holder.

Step 702: and acquiring the electrical angle measured by a Hall sensor arranged on the pan-tilt.

Step 703: and determining the mechanical angle of a motor in the holder according to the magnetic coding value and the electric angle so as to control the holder shaft of the holder to rotate according to the mechanical angle.

The above steps 701 to 703 are described as follows:

in this embodiment, the corresponding relationship between the magnetic encoding value range and the electrical angle period may be preset, and the specific setting process may be referred to the second embodiment, which is not described in detail herein.

In the process of determining the mechanical angle of the motor in the holder, the magnetic encoding value measured by the magnetic encoding sensor can be firstly obtained, the electrical angle measured by the hall sensor can be simultaneously obtained, subsequently, the magnetic encoding value range to which the magnetic encoding value belongs is determined, then, the electrical angle period to which the magnetic encoding value range belongs is determined according to the corresponding relation between the preset magnetic encoding value range and the electrical angle period, and the mechanical angle of the motor in the holder can be determined according to the electrical angle period and the electrical angle.

With reference to table 1, for example, assuming that the obtained magnetic encoding value belongs to the magnetic encoding value range [ a4, a5], as can be seen from the corresponding relationship illustrated in table 1, the magnetic encoding value range [ a4, a5] belongs to the third electrical angle period, then the mechanical angle of the motor in the pan/tilt head can be calculated by the following formula (four).

Mechanical angle ═ electrical angle/number of antipodes +180 ° formula (four)

In addition, it should be noted that, if the currently acquired magnetic encoding value does not belong to any effective magnetic encoding value range, in this case, the embodiment of the present invention proposes: and determining the magnetic encoding value which is acquired at the previous time and belongs to the range of the effective magnetic encoding value, determining the electric angle period to which the magnetic encoding value belongs, and then determining whether the electric angle period between the sampling moments of the previous time and the sampling moments of the next time jumps or not and the specific jump situation according to the electric angles measured at the previous time and the next time, thereby calculating the electric angle period to which the currently acquired magnetic encoding value belongs.

Specifically, first, for convenience of description, the currently acquired magnetic encoding value is recorded as Ai, and the currently acquired electrical angle is recorded as E_iRecording the magnetic encoding value which is obtained last time and belongs to the effective magnetic encoding value range as A_jWill be reacted with A_jThe electrical angle obtained at the same time is recorded as E_j。

If A is above_jAnd A_iAre adjacent, then E can be determined directly_jAnd E_iWhether the difference between them is greater than a preset threshold, for example 180 °, if so, it can be assumed that a jump in the electrical angle period has occurred, and it can be determined according to E_jAnd E_iThe size relationship between the two determines the jumping direction of the electrical angle period; if E_jAnd E_iIf the difference between the two values is not greater than the preset threshold, it can be considered that the value is notA jump in the electrical angle period occurs. Based thereon, according to A_jThe affiliated electrical angle period can determine A_iThe electrical angle period.

If the above-mentioned E is_jAnd E_iAre not adjacent, then it can be determined that E is located at_jAnd E_iIs determined at E, the electrical angle obtained at other sampling instants between the sampling instants of_jAnd E_iWhether the electrical angle period jumps or not, and the specific jump times and the jump direction of each electrical angle period when the jumps occur. For example, assume A_jBelonging to the second electrical angle period, let E_jAnd E_iHas a sampling time between the sampling times, and the electrical angle obtained at the sampling time is recorded as E_mAnd the magnetically encoded value is denoted A_mAnd assume E_mAnd E_jA difference therebetween is greater than a preset threshold value, and E_mLess than E_jAccordingly, it can be determined that in A_jAnd A_mA transition of one electrical angle period occurs in between, and is from the second electrical angle period to a third electrical angle period; suppose again E_mAnd A_iThe difference between them is not greater than the preset threshold, and accordingly, it can be determined that A is_mAnd A_iThere is no jump in electrical angle period between them, that is, A_iAnd A_mThe electrical angle periods are the same, i.e. the third electrical angle period.

Through the above description, the embodiment of the present invention may also implement determining an electrical angle period to which the magnetic encoding value belongs when the currently acquired magnetic encoding value does not belong to any effective magnetic encoding value range, and then determining the current mechanical angle of the motor according to the electrical angle period to which the magnetic encoding value belongs.

Based on the same inventive concept as the above-mentioned mechanical angle detection method, an embodiment of the present invention further provides a pan/tilt head, as shown in fig. 8, the pan/tilt head 800 includes a motor 810 and a pan/tilt head shaft 820, and the pan/tilt head further includes: a magnetic encoding sensor 830, a hall sensor 840, and a processor 850.

The magnetic encoding sensor 830 is configured to measure a magnetic encoding value;

the Hall sensor 840 is used for measuring to obtain an electrical angle;

and the processor 850 is configured to determine a mechanical angle of a motor in the pan/tilt head according to the magnetic encoding value and the electrical angle, so as to control a pan/tilt head shaft of the pan/tilt head to rotate according to the mechanical angle.

In one embodiment, the processor 850 is configured to: and determining an electrical angle period to which the magnetic encoding value belongs, and determining a mechanical angle of a motor in the holder according to the electrical angle period and the electrical angle.

In one embodiment, the processor 850 is configured to: determining a magnetic encoding value range to which the magnetic encoding value belongs; and determining the electric angle period to which the magnetic encoding value belongs according to the corresponding relation between the preset magnetic encoding value range and the electric angle period.

In one embodiment, the processor 850 is configured to: when the holder is in a set state, controlling the motor to rotate to a first limit position, and recording a first magnetic coding value currently measured by the magnetic coding sensor;

controlling the motor to rotate from the first limit position to a second limit position, acquiring a plurality of electrical angles measured by the Hall sensor at a set first sampling frequency in the process that the motor rotates from the first limit position to the second limit position, and acquiring a plurality of magnetic encoding values measured by the magnetic encoding sensor at the first sampling frequency;

if the difference value between the currently acquired electrical angle and the acquired previous electrical angle is larger than a preset threshold value, recording a plurality of second magnetic coding values acquired at the same time as the previous electrical angle, and recording a plurality of third magnetic coding values acquired at the same time as the currently acquired electrical angle;

when the motor rotates to the second limit position, recording a fourth magnetic encoding value currently measured by the magnetic encoding sensor;

and determining an effective magnetic encoding value range according to the first magnetic encoding value, the second magnetic encoding value, the third magnetic encoding value and the fourth magnetic encoding value, and determining an electric angle period corresponding to the effective magnetic encoding value range.

In one embodiment, the setting state includes: a first power-up state.

In one embodiment, the processor 850 is configured to: and controlling the motor to rotate from the first limit position to the second limit position at a set angular speed.

In one embodiment, the processor 850 is configured to: sequencing the first magnetic coding value, the second magnetic coding value, the third magnetic coding value and the fourth magnetic coding value according to the sampling sequence;

according to the sequencing result, dividing every two adjacent magnetic coding values into a group to obtain a plurality of groups;

and for each group, if the magnetic coding values obtained by other sampling exist between the two magnetic coding values in the group, determining the magnetic coding value range corresponding to the group as an effective magnetic coding value range.

In one embodiment, the processor 850 is configured to: determining an effective range of magnetic encoding values to which the magnetic encoding values belong.

In one embodiment, the processor 850 is further configured to: calculating the variance of the magnetic coding values of the set number according to the magnetic coding values measured by the magnetic coding sensors of the set number;

and if the variance exceeds a preset variance threshold, controlling the motor to rotate to a set position, and returning to the step of acquiring the magnetic code values measured by the magnetic code sensors in the set number until the variance of the magnetic code values in the set number does not exceed the variance threshold.

In one embodiment, the processor 850 is configured to: when the holder is in an initial state, acquiring an initial magnetic encoding value measured by a magnetic encoding sensor arranged on the holder;

and when the holder is in an initial state, acquiring an initial electrical angle measured by a Hall sensor arranged on the holder.

In one embodiment, the processor 850 is configured to: and determining an initial mechanical angle of a motor in the holder according to the initial magnetic coding value and the initial electrical angle.

In one embodiment, the processor 850 is configured to: if the magnetic encoding value is determined not to belong to any effective magnetic encoding value range, controlling the motor to rotate by a set angle;

acquiring the initial magnetic encoding value measured by the magnetic encoding sensor again;

and if the magnetic encoding value acquired again does not belong to any one of the effective magnetic encoding value ranges, continuing to execute the step of controlling the motor to rotate by the set angle until the acquired magnetic encoding value belongs to one of the effective magnetic encoding value ranges.

In one embodiment, the processor 850 is configured to: when the holder is in a working state, acquiring an electrical angle measured by a Hall sensor arranged on the holder at a set second sampling frequency; and determining the current mechanical angle of a motor in the holder according to the electrical angle and the initial mechanical angle.

In one embodiment, the processor 850 is configured to: determining an electrical angle variation between the currently acquired electrical angle and the initial electrical angle;

determining the mechanical angle variation according to the electrical angle variation and the number of antipodes of a motor in the holder;

and determining the current mechanical angle of the motor in the holder according to the initial mechanical angle of the motor in the holder and the mechanical angle variation.

In one embodiment, the processor 850 is further configured to: after the Hall sensor fails, acquiring a magnetic encoding value measured by the magnetic encoding sensor;

and determining the current mechanical angle of the motor in the holder according to the incidence relation between the magnetic coding value and the preset magnetic coding value and the mechanical angle.

In one embodiment, the processor 850 is configured to: when the holder is in a set state, controlling the motor to rotate to a first limit position;

controlling the motor to rotate from the first limit position to a second limit position, and acquiring a mechanical angle measured by the Hall sensor in the process that the motor rotates from the first limit position to the second limit position;

acquiring a magnetic encoding value measured by the magnetic encoding sensor;

determining an association between the magnetically encoded value and the mechanical angle.

In one embodiment, the processor 850 is configured to: and acquiring the mechanical angle measured by the Hall sensor at a set third sampling frequency.

In one embodiment, the processor 850 is configured to: and acquiring the magnetic coding value measured by the magnetic coding sensor at the third sampling frequency.

In one embodiment, the processor 850 is configured to: and establishing a corresponding relation between the magnetic coding value and the mechanical angle acquired at the same sampling moment.

In one embodiment, the processor 850 is configured to: sequencing the corresponding relations according to the sequence of the magnetic coding values in each corresponding relation from small to large;

searching a sequencing result according to the magnetic coding value, and finding that the magnetic coding value is positioned between a fifth magnetic coding value and a sixth magnetic coding value;

acquiring a fifth mechanical angle corresponding to the fifth magnetic coding value and acquiring a sixth mechanical angle corresponding to the sixth magnetic coding value;

and performing linear interpolation according to the linear relation between the fifth mechanical angle and the sixth mechanical angle to obtain the current mechanical angle of the motor in the holder.

In one embodiment, the magnetic encoder sensor is located on an axial side of a rotating shaft in the motor.

Based on the same inventive concept as the mechanical angle detection method, an embodiment of the present invention further provides a machine-readable storage medium, where the machine-readable storage medium may be located in a pan-tilt head, and the machine-readable storage medium stores a plurality of computer instructions, and when executed, the computer instructions perform the following processes: acquiring a magnetic coding value measured by a magnetic coding sensor arranged on the holder; acquiring an electrical angle measured by a Hall sensor arranged on the holder; and determining the mechanical angle of a motor in the holder according to the magnetic coding value and the electrical angle so as to control a holder shaft of the holder to rotate according to the mechanical angle.

In an embodiment, in the process of acquiring the magnetic encoding value measured by the magnetic encoding sensor arranged on the pan/tilt head, the computer instructions are further executed to: when the holder is in an initial state, acquiring an initial magnetic encoding value measured by a magnetic encoding sensor arranged on the holder;

In one embodiment, in determining the mechanical angle of the motor in the head from the magnetically encoded values and the electrical angle, the computer instructions when executed perform the following: and determining an electrical angle period to which the magnetic encoding value belongs, and determining a mechanical angle of a motor in the holder according to the electrical angle period and the electrical angle.

In one embodiment, in said determining the electrical angle period to which the magnetically encoded value belongs, the computer instructions when executed perform the following: determining a magnetic encoding value range to which the magnetic encoding value belongs; and determining the electric angle period to which the magnetic encoding value belongs according to the corresponding relation between the preset magnetic encoding value range and the electric angle period.

In one embodiment, in presetting the correspondence between the magnetic encoding value range and the electrical angle period, the computer instructions are executed to perform the following processes: when the holder is in a set state, controlling the motor to rotate to a first limit position, and recording a first magnetic coding value currently measured by the magnetic coding sensor;

In one embodiment, the setting state includes: a first power-up state.

In one embodiment, in said controlling said motor to rotate from said first limit to said second limit, said computer instructions when executed perform the following: and controlling the motor to rotate from the first limit position to the second limit position at a set angular speed.

In one embodiment, in said determining a range of valid magnetically encoded values from said first, second, third and fourth magnetically encoded values, said computer instructions when executed perform the following: sequencing the first magnetic coding value, the second magnetic coding value, the third magnetic coding value and the fourth magnetic coding value according to the sampling sequence;

In one embodiment, in said determining the range of magnetically encoded values to which the initial magnetically encoded value belongs, the computer instructions when executed perform the following: determining a range of valid magnetic encoding values to which the initial magnetic encoding value belongs.

In one embodiment, prior to controlling the process of rotating the motor to the first limit, the computer instructions when executed further perform the following: calculating the variance of the magnetic coding values of the set number according to the magnetic coding values measured by the magnetic coding sensors of the set number;

In an embodiment, the magnetic encoding value is an initial magnetic encoding value measured by a magnetic encoding sensor provided on the pan/tilt head, which is obtained when the pan/tilt head is in an initial state.

In one embodiment, in said determining the range of valid magnetically encoded values to which the initial magnetically encoded value belongs, the computer instructions when executed perform the following: if the initial magnetic encoding value is determined not to belong to any effective magnetic encoding value range, controlling the motor to rotate by a set angle;

and if the initial magnetic encoding value acquired again does not belong to any one of the effective magnetic encoding value ranges, continuing to execute the step of controlling the rotation set angle of the motor until the acquired initial magnetic encoding value belongs to one of the effective magnetic encoding value ranges.

In one embodiment, in the process of acquiring the magnetic encoding value measured by the magnetic encoding sensor arranged on the pan/tilt head, the computer instructions are executed to perform the following processing: when the holder is in an initial state, acquiring an initial magnetic encoding value measured by a magnetic encoding sensor arranged on the holder;

in the process of acquiring the electrical angle measured by the hall sensor arranged on the holder, the computer instructions are executed to perform the following processing: and when the holder is in an initial state, acquiring an initial electrical angle measured by a Hall sensor arranged on the holder.

In one embodiment, in determining the mechanical angle of the motor in the head from the magnetically encoded values and the electrical angle, the computer instructions when executed perform the following: and determining an initial mechanical angle of a motor in the holder according to the initial magnetic coding value and the initial electrical angle.

In one embodiment, in determining the mechanical angle of the motor in the head from the magnetically encoded values and the electrical angle, the computer instructions when executed perform the following: when the holder is in a working state, acquiring an electrical angle measured by a Hall sensor arranged on the holder at a set second sampling frequency; and determining the current mechanical angle of a motor in the holder according to the electrical angle and the initial mechanical angle.

In one embodiment, in the determining the current mechanical angle of the motor in the pan/tilt head according to the electrical angle and the initial mechanical angle of the motor in the pan/tilt head, the computer instructions when executed perform the following: determining an electrical angle variation between the currently acquired electrical angle and the initial electrical angle; determining the mechanical angle variation according to the electrical angle variation and the number of antipodes of a motor in the holder; and determining the current mechanical angle of the motor in the holder according to the initial mechanical angle of the motor in the holder and the mechanical angle variation.

In one embodiment, the computer instructions when executed further perform the following: after the Hall sensor fails, acquiring a magnetic encoding value measured by the magnetic encoding sensor;

In one embodiment, in presetting the association relationship between the magnetic encoding value and the mechanical angle, the computer instructions when executed perform the following processes:

when the holder is in a set state, controlling the motor to rotate to a first limit position;

acquiring a magnetic encoding value measured by the magnetic encoding sensor;

In one embodiment, in the process of acquiring the mechanical angle measured by the hall sensor, the computer instructions are executed to perform the following processes: and acquiring the mechanical angle measured by the Hall sensor at a set third sampling frequency.

In one embodiment, in the acquiring the magnetic encoding value measured by the magnetic encoding sensor, the computer instructions are executed to: and acquiring the magnetic coding value measured by the magnetic coding sensor at the third sampling frequency.

In one embodiment, in said determining the association between the magnetically encoded value and the mechanical angle, the computer instructions when executed perform the following: and establishing a corresponding relation between the magnetic coding value and the mechanical angle acquired at the same sampling moment.

In an embodiment, in the process of determining the mechanical angle of the motor in the pan/tilt head according to the association relationship between the magnetic encoding value and the preset magnetic encoding value and mechanical angle, the computer instructions are executed to perform the following processes: sequencing the corresponding relations according to the sequence of the magnetic coding values in each corresponding relation from small to large;

For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The method and apparatus provided by the embodiments of the present invention are described in detail above, and the principle and the embodiments of the present invention are explained in detail herein by using specific examples, and the description of the embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A mechanical angle detection method is characterized by being applied to a holder provided with a Hall sensor and a magnetic coding sensor, and comprising the following steps:

2. The method of claim 1, wherein the magnetic encoding sensor is positioned on a medial side of the head.

3. The method according to claim 1, characterized in that the magnetic coding sensor is calibrated using the mechanical angle measured by the hall sensor when the head is in a first power-up state.

4. The method of claim 1, wherein the calibrating the magnetically encoded sensor using the mechanical angle measured by the hall sensor comprises:

5. The method according to claim 4, wherein said determining the mechanical angle of the motor of the head from the magnetic encoding values measured by the calibrated magnetic encoding sensor comprises:

6. The method according to claim 4, characterized in that the mechanical angle and the state of the electric machine indicated by the magnetically encoded value, taken at the same sampling instant, are the same.

7. The method of claim 4 or 6, wherein said calibrating said magnetically encoded sensor comprises:

8. The method of claim 7, wherein there are a plurality of pairs of correspondences between the mechanical angles and the magnetically encoded values;

9. The method of claim 8, wherein the fifth magnetic encoding value is a largest one of all magnetic encoding values that are less than the magnetic encoding value measured by the magnetic encoding sensor;

10. The method according to claim 8, characterized in that the mechanical angle of the motor of the pan/tilt head is obtained by linear interpolation according to the linear relationship between the mechanical angle corresponding to the fifth magnetic encoding value and the mechanical angle corresponding to the sixth magnetic encoding value.

11. The method of claim 1, further comprising:

12. A cloud platform is characterized in that the cloud platform comprises a motor, a magnetic coding sensor, a Hall sensor and a processor;

the Hall sensor is used for measuring to obtain a mechanical angle;

the Hall sensor is used for measuring to obtain a magnetic coding value;

13. A machine-readable storage medium having stored thereon computer instructions which, when executed, implement the method of detecting a mechanical angle according to any one of claims 1 to 11.